ARLINGTON -- Frustration in the Mariners clubhouse was as thick as the muggy air on a 93-degree night at Rangers Ballpark on Monday after Seattle lost its fifth straight game, this time a 4-2 decision to Texas.Lack of offensive progress, compounded by a critical eighth-inning play when Brendan Ryan was thrown out at the plate trying to pull off an inside-the-park home run with nobody out, had the Mariners kicking themselves after another rough go against Rangers left-hander Matt Harrison. Harrison beat Seattle for a seventh straight time and improved to 8-1 with a 2.51 ERA in his career against his American League West foe, but the Mariners felt as if they contributed to their demise in this one. "Who knows what happens if we score there," Ryan said of his foiled attempt to leg out his first career inside-the-park homer. "Maybe we have a small parade in the dugout and, boom, now there's electricity and we take off from there and all the momentum goes our way. Who knows?" Third-base coach Jeff Datz took the bullet for sending Ryan after center fielder Craig Gentry missed a diving attempt at his line drive and the ball rolled to the wall. Michael Saunders scored from first to cut the score to 4-2, but the Rangers threw out Ryan at the plate when the safe play would have been to hold him up with nobody out. "He's always going to be all out," manager Eric Wedge said of Ryan. "But obviously if we're going to send him there, he needs to be safe in that situation." "I don't like to use the word never or always, but you really don't want to make the first out at home plate, and I did that," Datz said. "I felt at the time he was going to make it. That's why I sent him, but it didn't happen that way." Ryan seemed to lose speed coming around third and said he looked for an extra gear that just wasn't there. He wound up being blocked at the plate by catcher Mike Napoli on a perfect relay throw from second baseman Ian Kinsler. "I love getting the opportunity, and I hate that it cost us an out and maybe a run," Ryan said. "For Datzy's sake, we're not getting 15 hits a game. I want to compare it to coming off the bench with limited at-bats, limited opportunities of knowing when to be aggressive and all that stuff. I don't blame him at all. That's a tough call." The Mariners certainly were having trouble getting to Harrison any other way, as he scattered seven hits with no walks and five strikeouts over eight innings. Napoli's three-run homer off reliever Steve Delabar in the sixth inning provided all the punch Texas needed to win its fourth straight. Mariners starter Kevin Millwood held Texas to just one run, but needed 97 pitches to get through five innings and turned a tie game over to the bullpen in the sixth. "They're just really selective and didn't chase any bad pitches and I didn't locate very well today," said Millwood. "The two combined just added up to me throwing a lot of pitches. You can't give in and just start throwing the ball down the middle. You just keep doing what you're doing and try to fix it and get deep in the ballgame. But I wasn't able to do that either." Delabar got in quick trouble with a walk to Adrian Beltre and base hit to David Murphy before Napoli drove a 2-0 fastball 401 feet the opposite way off the right-field facade. It was the seventh home run given up by Delabar in 24 1/3 innings as his ERA climbed to 5.18. Seattle (21-30) took two of three from Texas last week at Safeco Field, but the Mariners have now lost 13 of their past 15 at Rangers Ballpark and haven't won a series here since 2010. Millwood shut out the Rangers for six innings on three hits on Wednesday in a 3-0 win, which was Seattle's last victory. He ran his scoreless streak to 18 innings -- equaling his career best -- until Nelson Cruz hit a home run down the right-field line in the second. That was the lone run allowed by the veteran right-hander, who remains 3-4 on the year with a 3.56 ERA. The Mariners had taken a 1-0 lead on an RBI single by rookie catcher Jesus Montero in the first. But other than Ryan's RBI triple, that was the only production Seattle got on a night they only had two at-bats with runners in scoring position. Thus Seattle had no margin of error, which isn't a good situation for such a young team. "It's the same old story," Wedge said. "These guys are going to have to dig deep and find a way to put into play what we want them to do offensively. We've talked to them about it, we've explained it to them, I think they have a good understanding of what they need to do, but making sure that translates into games, that's what we're not seeing. "And that's the frustrating part for me as the manager of this ballclub. Because to win in the big leagues, you can't have to play perfect [all the time]. The only way you can do that is to be better and more consistent offensively."